Kinetics and deuterium kinetic isotope effects for the thermal [1,7] sigmatropic rearrangements of cis,cis-1,3,5-octatriene
作者:John E. Baldwin、V. Prakash Reddy
DOI:10.1021/ja00260a017
日期:1987.12
and E/sub a/ = 20.2 kcal mol/sup -1/ (to cis,cis,trans-2,4,6-octatriene). Primary deuterium kinetic isotope effects for these (1,7) sigmatropic shifts are found to be 6.4-7.7 and not markedly temperature dependent, indicative of a linear or nearly linear C7-H-C1 geometry in the transition-state structure.
cis,cis-1,3,5-辛三烯在 60-111/sup 0/C 下发生热异构化,活化参数 log A = 9.1 和 E/sub a/ = 21.3(到 cis,cis,cis-2,4 ,6-辛三烯)和 E/sub a/ = 20.2 kcal mol/sup -1/(顺式、顺式、反式-2,4,6-辛三烯)。发现这些 (1,7) sigmatropic 位移的主要氘动力学同位素效应为 6.4-7.7 并且不显着依赖于温度,表明过渡态结构中的线性或接近线性的 C7-H-C1 几何形状。